Of course it's always important to protect your identity by keeping your information safe.
But if it's too late, there are four things you should do immediately.
First, place a fraud alert on your credit report and get a copy of your report. This lets you see what kind of damage has been done and prevents thieves from opening more accounts in your name.
Next, close the accounts that you know or believe have been tampered with. You can talk to someone in the security or fraud deparment of a company to do this.
You then need to file a complaint with the Federal Trade Commision. This will help law enforcement officials track down theives.
Finally, file a report with your local police or the community where the identity theft took place.